Reflector for radiant heating



Jan. 2, 1962 R. A. BRIDWELL REFLECTOR FOR RADIANT HEATING 2 Sheets-Sheet 1 Filed March 3, 1959 Jan. 2, 196 R. A. BRIDWELL REFLECTOR FOR RADIANT HEATING 2 Sheets-Sheet 2 Filed March 3, 1959 ELL l l L United States Patent 3,015,711. REFLECTOR FOR RADIANT HEATING Robert A. Bridwell, Lynwood, Califi, assignor to Northrop Corporation, Beverly Hills, Califi, ,a corporation of California Filed Mar. 3, 1959, Set. No. 796,880 1 Claim. (Cl. 219-34) This invention relates to heating devices and more particularly to a reflector assembly having utility in carrying out a radiant heating operation.

It is well known in the metal working art that certain metals and their alloys-must be heated to a predetermined temperature if they are to be fabricated successfully. This is particularly true of titanium andmagnesium sheets and alloys thereof if they are to be fabricated without the oc- 4 In addition to" currence of fractures, cracks, tears, etc. the above other unusual conditions are encountered in the fabrication of titanium, manganese and like sheets.

For example, if titanium or manganese sheets are heated to a maximum allowable temperature and subsequently allowed to cool to a lower temperature prior to fabricait is necessary to utilize a reflector assembly of the type disclosed herein. Such a reflector assembly embodies novel cooling features and is of light weight construction rendering it easily movable between heating and non-heating positions.

An object of this invention is to provide a reflector assembly usable in carrying out a radiant heating operation which includes a reflector panel mounted in the assembly in a manner allowing adequate thermal expansion thereof without excessive restriction and which can be easily and quickly removed from the assembly for polishing or replacement thereof.

Another object is to provide a reflector assembly usable in carrying out a radiant heating operation which includes a reflector panel the non-reflecting side of which embodies means which materially improves the heat emitting qualities thereof.

Another object is to provide a reflector assembly usable in carrying out a radiant heating operation which embodies means for cooling the assemblys reflector and separate cooling means for the heating elements, particularly their end portions.

Another object is to provide a reflector assembly usable in carrying out a radiant heating operation which is of light weight construction and, therefore, is easily and quickly movable by mechanical means.

Although the characteristic features of the present invention are particularly pointed out in the appended claim, the invention itself, also the manner in which it may be carried out, will be better understood by referring to the following description taken in connection with the accompanying drawings forming a part of this application and in which:

FIGURE 1 is a plan view of the reflector assembly as disclosed herein with portions broken away to clarify the construction thereof.

FIGURES 2 and 3 are side and end views, respectively, of the reflector assembly shown in FIGURE 1 with por- 3,015,711 Patented Jan. 2, 1962 3110115 of FIGUREZ broken away for clarification purposes. e

FIGURES 4 and 5 are sectional views of the reflector assembly taken on the lines 4-4 and 55, respectively, 5 of FIGURE 1.

7 Referring now to the drawings, a preferred embodiment of the reflector assembly as disclosed herein is identified in its entirety by the numeral 11. The reflector assembly includes a housing structure 12, a reflector panel -1 14 and arm'memberslfi which enable the assembly 11 to ,r be mounted in operating apparatus of a type as disclosed in the aforementioned copending application.

In the embodiment shown the structure 12 constitutes an elongated structure of shallow box-like configuration.

15 The structure 12 is further characterized in that it is constructed of sheet metal and includes a top 17, sides 18 and 19 and ends 21 and 22 all of which are solid except for outlet ports formed therein. The lower side of the structure 12, as viewed in'FIGURES 2, 4 and 5, is unobstructed except for structure defining cooling passages or ducts 2424 to be described later. Mounted'on the top 17, extending lengthwise of the structure 12 at locations adjacent the sides .18 and 19, are a pair of strengthening strips 23-23.

25 Formed inside thestructure 12, extending lengthwise .g thereof and at positions adjacent sides'l8 and 19, are the aforementioned passages 24-24 adapted to carry. air or other fluidfor cooling. the ends of the heating members 26. ,The passages 2424' are defined by the sides 18 and 19.,and anglestrips 27, 28 and 29 as best seen in FIGURE The; strips 27, 28:and 29 are secureditogether' as by. wcldingor the like and terminate in abutting relation with respect to the ends 21 and '22. Thus it will be seen that the strips 27, 28 and 29 cooperate with the sides 18 and 19 to define respective passages located at each side of the structure. 12' and extend the fulllength thereof.

The reflector panel 14 constitutes a metallic member of shallow U-shaped configuration in section as viewed in FIGURE 4. The panel is mounted in the structure 12 0 in an inverted position between the passages 2424 with edge portions of its upper surface frictionally contacting the strips 28-28. The panel is held in this position by bolt means 31, which pass through the ends 21 and 22 and the arcuate terminal ends of the panel 14 and by sheet metal screws 32 and clips 3333 which depend from the top 17. Inasmuch as the panel 14 is not secured to the strips 28 it will be apparent that the panel may be easily and quickly removed for polishing or replacing by removing the bolt means 31 and screws 32. It will also be seen that the arcuate ends of the panel 14 and the clips 33 allow limited expansion of the panel so that the latter is not unduly restrained as the panel expands during a heating operation.

The lower surface of the panel 14 is highly polished to reflect a maximum of heat emitted by the members 26. The upper or non-reflecting side of the panel 14 is grooved in a longitudinal direction as indicated by the numeral 30 and coated with a material increasing the heat emitting qualities thereof.

As positioned in the structure 12 the panel 14 cooperates with the top 17 and strips 2929 to define a passage 34 which extends the full length of the structure 12 to provide means for cooling the panel 14.

Apertures 36 and 37 are provided in the ends 21 and 22 and communicate respectively with the passages 24 and 34 to provide exit ports for air or other cooling fluid flowing through the passages 24 and 34.

Mounted on top of the structure 12 is a distribution head 35 for diverting air or other cooling fluid to the 70 passages 24 and 34. Air at super-atmospheric pressure, orlginatinig at a pressure source (not shown), is directed to the head 35 through a supply conduit 40. From a common chamber or bore located in the head 35th'pressurized air flows directly to the pas-sages Z4-.-24 via conduits 38 and 39 which enter the passages at approximately their midpoint. Pressurized air directed to the passage 34 flows throughfcondui-ts 41 and '42 which terminate 'in elbow type pipe fittings 43 which in turn communicatewith the passage34." The arrangement of the ends of'the conduits 41' and 42' with respect to thefittings'43 is such that as air flows from the conduits 41 and 42 it provides' anaspira-ting eficct drawing .arnbieht air into the-pas sage: 34. Therefore,*the'panel 14 .is not only cooled by pressurized air flowing through the conduits 4 l and 42 bu't also by ambient air. In the instant reflector assembly'heatis"provided-by energizing a plurality 'of quartz type heating members 26.

The members 26" are'mount'ed directly belowthe panel 3 14 and"extend'lateral1y of the structure 12' with their ends which depend from-horizontal portions of the strips29.

f respectivelymounted in the passaiges M -24.: The endsv:

of -the heatingmembers are sec-uredin receptacles 44 Construction-of theas's'embly 11 is complete'dby two arm-members 46-and 47f which are welded'to and'extendn I fronrthe'st-ructure 12 in "a lateral dire'ctionw Both of the arm membersca'rry bearing means at their 'outer ends' and the' m'ember 47 also rcari'iesa'cable' receiving sheave" 48:" The-arm members 46- and 47 provide means whereb thevrefie'ctor; assembly mayrnbe' mounted *in suitable op 'erating apparatus.

Frorh'the' above description it='will*be seen tli'at a reflector assembly fulfilling the manytolijects' of theinven tion is provided. ,With a reflector"assemblyfiof the'above type the temperatttreof titanium sheets 'has' been'raised" from roomtemp'eratu re to 1500 F; yet the temperature V of' the'panel 14 has not exceeded 500 F.- Theabove' re? ;sults have been achieved intests of five (5)" minutes'con tinuous duration'or sixty (60), minute intermittent duty:

with the heating members 26 cycling bnfl andbfi'ffdr "appr'oxirnately one andone-half -(1 /2) minutespercycle; While in order 'to complywith the statute the' inven tion has been described in language more of lessspecific as 't-oht'r'htiiral"features,"it'is to be ufi'deir'st doddhat' the" invention is not limited to the specific features shown,

but that the means and construction herein disclosed comprise a preferred form of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the' legitirnate and valid scope of the ppended-claim; a

In a refiectbrassemb-lythe'cornbination com'prising:,a bottomless box-like housing having top, sidel anden'd walls; plate means-cooperatingwi-th said 'side'and end walls to partially close the bottom side of said housing and defineel-ongated rninorcham'bers adjacent each side wall iof said housing; a reflector plate *mountcd err-said housing closing the remainderot said bottom side :and i cooperatingr'rwith said'platemeanstop. and end walls to define a major chamber; conduit means-communicating: with said'minor-chambersadapted'to deliver-pressurized fluid to said minor chambers;;-conduit means cornriiuni-= eating with said major-"chamber adapted todeliver prest surizedfiuid to said major chamber; said--"la'st named" conduit meansincluding T aspirator means whereby ambient fluid is also caused 'toenter-said major'whambenfland -at least one of said cnd walls"defining apertures" through which fluid mayexit -from 'said-major-and minor chambers.

g rems Cit 'cdfin the are of this ate U ED' STA- TE'S PATENTS' I redee 

